Spearmint (Mentha spicata L.) and peppermint (Mentha piperita L.) have important biological activities. They are commonly consumed as herbal teas. This study was designed to produce ready to drink iced teas rich in bioactive compounds by using microencapsulated spearmint and peppermint extracts. Pressurized hot water extracts of spearmint and peppermint were processed into microencapsulated powders using spray drying. Iced teas were produced by using the microencapsulated extracts, sucrose and citric acid. In addition, the effects of the use of microencapsulated lemon extract (MLE) instead of citric acid were studied to evaluate the potential application of MLE on iced tea production. Total phenolic content (TPC) of iced teas ranged between 27.37 and 46.31 mg gallic acid equivalents/100 mL. Antioxidant capacities (as EC₅₀ and Trolox equivalent) of iced teas were between 389–481 mL/g DPPH and 55.33–80.88 mg Trolox equivalents/100 mL. The main phenolic compound was rosmarinic acid in spearmint iced teas, whereas eriocitrin was the main phenolic in peppermint iced teas. MLE usage increased TPCs, antioxidant activities and eriocitrin contents of iced teas. HPLC analysis showed hydrolysis of sucrose to invert sugar (fructose and glucose) during the production of the iced teas. Carvone amount (0.30–0.32 mg/100 mL) in spearmint iced teas and sum of menthol, menthone and methyl acetate (6.51–6.75 mg/100 mL) in peppermint iced teas were measured by GC–FID. The sensory results showed that no significant differences were between iced teas with citric acid and iced teas with MLE. Peppermint iced teas were characterized by nasal and oral cooling sensations.

中文翻译：

---

即饮型微胶囊留兰香（Mentha spicata L.）和薄荷（Mentha piperita L.）提取物的冰茶：物理化学，生物活性和感官特性

薄荷（Mentha spicata L.）和薄荷（Mentha piperitaL.）具有重要的生物活性。它们通常作为凉茶食用。本研究旨在通过使用微囊化的留兰香和薄荷提取物来生产即饮型富含生物活性化合物的冰茶。使用喷雾干燥将留兰香和薄荷的加压热水提取物加工成微囊化粉末。通过使用微囊提取物，蔗糖和柠檬酸生产冰茶。此外，研究了使用微囊柠檬提取物（MLE）代替柠檬酸的效果，以评估MLE在冰茶生产中的潜在应用。冰茶的总酚含量（TPC）为27.37至46.31 mg没食子酸当量/ 100 mL。抗氧化能力（如EC ₅₀冰茶的含量为389-481 mL / g DPPH和55.33-80.88 mg Trolox当量/ 100 mL。留兰香冰茶中的主要酚类化合物为迷迭香酸，而薄荷茶中的主要酚类成分为苦橙苷。MLE的使用增加了冰茶的TPC，抗氧化剂活性和芥子苷含量。HPLC分析表明，在冰茶的生产过程中，蔗糖水解成糖（果糖和葡萄糖）。通过GC-FID测量留兰香冰茶中的香芹酮含量（0.30–0.32 mg / 100 mL）和薄荷冰茶中的薄荷醇，薄荷酮和乙酸甲酯的总含量（6.51–6.75 mg / 100 mL）。感官结果表明，柠檬酸冰茶和MLE冰茶之间没有显着差异。薄荷冰茶具有鼻腔和口腔清凉感。